From: Vasily Khoruzhick <anarsoul@gmail.com>
To: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Jagan Teki <jagan@amarulasolutions.com>,
maarten.lankhorst@linux.intel.com, sean@poorly.run,
David Airlie <airlied@linux.ie>, Rob Herring <robh+dt@kernel.org>,
Chen-Yu Tsai <wens@csie.org>, Icenowy Zheng <icenowy@aosc.io>,
Jernej Skrabec <jernej.skrabec@siol.net>,
thierry.reding@gmail.com, Mark Rutland <mark.rutland@arm.com>,
dri-devel <dri-devel@lists.freedesktop.org>,
devicetree <devicetree@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
arm-linux <linux-arm-kernel@lists.infradead.org>,
Michael Nazzareno Trimarchi <michael@amarulasolutions.com>,
TL Lim <tllim@pine64.org>,
linux-sunxi@googlegroups.com, linux-amarula@amarulasolutions.com
Subject: Re: [PATCH v2 01/12] drm/sun4i: sun6i_mipi_dsi: Compute burst mode loop N1 instruction delay
Date: Tue, 20 Nov 2018 08:01:36 -0800 [thread overview]
Message-ID: <CA+E=qVc8c4u6yMw0Gtq41_vbV-zy7B8CLV0WadFCqRfSR2LPgQ@mail.gmail.com> (raw)
In-Reply-To: <20181120155826.j5rja22jnxpkmjrs@flea>
On Tue, Nov 20, 2018 at 7:59 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Tue, Nov 20, 2018 at 07:06:30PM +0530, Jagan Teki wrote:
> > On Tue, Nov 20, 2018 at 6:53 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > >
> > > On Mon, Nov 19, 2018 at 04:28:29PM +0530, Jagan Teki wrote:
> > > > On Mon, Nov 19, 2018 at 1:57 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > >
> > > > > On Fri, Nov 16, 2018 at 10:09:05PM +0530, Jagan Teki wrote:
> > > > > > Loop N1 instruction delay for burst mode lcd panel are
> > > > > > computed as per BSP code.
> > > > > >
> > > > > > Reference code is available in BSP (from linux-sunxi
> > > > > > drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)
> > > > > >
> > > > > > dsi_dev[sel]->dsi_inst_loop_num.bits.loop_n1=
> > > > > > (panel->lcd_ht-panel->lcd_x)*(150)/(panel->lcd_dclk_freq*8) - 50;
> > > > > > => (((mode->htotal - mode->hdisplay) * 150) /
> > > > > > ((mode->clock / 1000) * 8)) - 50;
> > > > > >
> > > > > > So use the similar computation for loop N1 delay.
> > > > > >
> > > > > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > > > >
> > > > > *why* are you doing this? What is it fixing? on which devices?
> > > >
> > > > You mentioned the separate function to compute the delay for all modes
> > > > [1], ie what I did. did I missing anything?
> > >
> > > You're missing that you are never explaining why that patch is needed
> > > in the first place. Or answering the question I asked a couple of
> > > lines above.
> >
> > OK.
> >
> > The instruction delay varies between video and burst mode. for burst
> > mode panels it is computed based on the panel clock along with
> > horizontal sync+porch timings.
>
> You're still stating a fact. What issue, that you experienced, are you
> trying to solve here?
IIRC that's what BSP driver does. Otherwise panels that use burst mode
just don't work.
> Maxime
>
> --
> Maxime Ripard, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
next prev parent reply other threads:[~2018-11-20 16:02 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-16 16:39 [PATCH v2 00/12] drm/sun4i: Allwinner MIPI-DSI Burst mode support Jagan Teki
2018-11-16 16:39 ` [PATCH v2 01/12] drm/sun4i: sun6i_mipi_dsi: Compute burst mode loop N1 instruction delay Jagan Teki
2018-11-19 8:27 ` Maxime Ripard
2018-11-19 10:58 ` Jagan Teki
2018-11-20 13:23 ` Maxime Ripard
2018-11-20 13:36 ` Jagan Teki
2018-11-20 15:58 ` Maxime Ripard
2018-11-20 16:01 ` Vasily Khoruzhick [this message]
2018-11-20 16:19 ` Jagan Teki
2018-11-16 16:39 ` [PATCH v2 02/12] drm/sun4i: sun6i_mipi_dsi: Support instruction loop selection Jagan Teki
2018-11-16 16:39 ` [PATCH v2 03/12] drm/sun4i: sun6i_mipi_dsi: Setup burst mode timings Jagan Teki
2018-11-19 8:30 ` Maxime Ripard
2018-11-19 11:00 ` Jagan Teki
2018-11-20 15:45 ` Maxime Ripard
2018-11-20 16:22 ` Jagan Teki
2018-11-27 10:07 ` Maxime Ripard
2018-11-16 16:39 ` [PATCH v2 04/12] drm/sun4i: sun6i_mipi_dsi: Simplify drq set to support all modes Jagan Teki
2018-11-19 8:32 ` Maxime Ripard
2018-11-19 11:22 ` Jagan Teki
2018-11-20 14:32 ` Maxime Ripard
2018-11-20 14:48 ` Jagan Teki
2018-11-16 16:39 ` [PATCH v2 05/12] drm/sun4i: tcon: Export get tcon0 routine Jagan Teki
2018-11-19 8:34 ` Maxime Ripard
2018-11-16 16:39 ` [PATCH v2 06/12] drm/sun4i: sun6i_mipi_dsi: Probe tcon0 during dsi_bind Jagan Teki
2018-11-19 8:38 ` Maxime Ripard
2018-11-19 11:36 ` Jagan Teki
2018-11-20 15:44 ` Maxime Ripard
2018-11-16 16:39 ` [PATCH v2 07/12] drm/sun4i: sun6i_mipi_dsi: Setup burst mode Jagan Teki
2018-11-16 16:39 ` [PATCH v2 08/12] drm/sun4i: sun6i_mipi_dsi: Enable 2byte trail for 4-lane " Jagan Teki
2018-11-16 16:39 ` [PATCH v2 09/12] drm/sun4i: sun6i_mipi_dsi: Enable burst mode HBP, HSA_HSE Jagan Teki
2018-11-16 16:39 ` [PATCH v2 10/12] dt-bindings: panel: Add Feiyang FY07024DI26A30-D MIPI-DSI LCD panel Jagan Teki
2018-11-16 16:39 ` [PATCH v2 11/12] drm/panel: " Jagan Teki
2018-12-10 16:12 ` Jagan Teki
2018-12-13 15:07 ` Sean Paul
2018-12-13 19:26 ` Jagan Teki
2018-12-13 19:55 ` Sean Paul
2018-12-14 11:05 ` Jagan Teki
2018-12-14 14:15 ` Sean Paul
2018-11-16 16:39 ` [PATCH v2 12/12][DO NOT MERGE] arm64: allwinner: a64: pine64-lts: Enable Feiyang FY07024DI26A30-D DSI panel Jagan Teki
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